The original phrase, Taggart said, was, ‘‘Eat an apple on going to bed, and you’ll keep the doctor from earning his bread.” In the 19th century and early 20th, the phrase evolved to “an apple a day, no doctor to pay” and “an apple a days sends the doctor away,” while the phrasing now commonly used was first recorded in 1922.

Although the term is fairly new, Taggart said, the concept is quite old. Ancient Romans and Anglo-Saxons, she said, knew about the healthful properties of apples. The fruit also pops up in traditional Ayurvedic medicine, dating back about 1,500 years in southern Asia.

The popularity of the phrase has not been lost on modern science, either. Researchers and doctors have conducted numerous studies on the health benefits of apples — exploring whether they can actually reduce trips to the doctor.